DESCRIPTION: A Methodology Core (MC) is proposed with the following specific aims: 1). To provide clinical investigators within and external to the MCRC a resource for obtaining conceptual, practical and technical assistance related to methodological and biostatistical issues of clinical investigation; 2.To design and implement an independent process for data and safety monitoring for MCRC clinical trials; 3.To promote interdisciplinary clinical research among persons and skill areas already in existence within the research base that results in synergism; 4.To offer regularly scheduled and informal educational opportunities in clinical research methodology and biostatistics designed for investigators, fellows graduate students and other staff. Long-term goals of the. MC are to increase the overall quality of clinical science and interdisciplinary research within the research base. The MC will build on the experience, resources and unique expertise of the existing Biometry Core that resides within the current Cincinnati MAMDC and the core of the Exploratory Research Center in Juvenile Rheumatic Disease that preceded the MAMDC. The proposed director of the MC, Dr. Edward H. Giannini, has been the director of each of these cores. MAMDC core personnel and individuals that will become part of the MCRC Methodology Core oversaw and participated in the development of each of the four proposed projects. This oversight and participation will continue throughout the project period via numerous mechanisms. These include: regularly scheduled and as needed, meetings of MC personnel with key personnel of each project, formalized educational program offerings, and performance of tasks such as database creation and biostatistical computing. Interactive leadership of the MC and projects will occur via an Internal Advisory Council and an Executive Committee of which the Director of the MC will be a member.